WO2019033878A1

WO2019033878A1 - Liner, reaction chamber and semiconductor processing equipment

Info

Publication number: WO2019033878A1
Application number: PCT/CN2018/095437
Authority: WO
Inventors: 赵晋荣; 常楷
Original assignee: 北京北方华创微电子装备有限公司
Priority date: 2017-08-17
Filing date: 2018-07-12
Publication date: 2019-02-21
Also published as: US20210193434A1; SG11202001343SA

Abstract

Provided in the present invention are a liner, a reaction chamber and semiconductor processing equipment, the liner being disposed in the reaction chamber, and comprising: a liner main body, surroundingly disposed at an inner side of a side wall of a reaction chamber, and grounded; a first separator, surrounding a base disposed in the reaction chamber, a lower end of the first sub-body being grounded via the base; in addition, a medium ring is surroundingly disposed between an inner circumferential wall of the first separator and an outer circumferential wall of the base; and a second separator, surroundingly disposed between a lower end of the liner main body and an outer peripheral wall of the first separator. The liner provided in the present invention can prevent resonance from occurring in a system, thereby strengthening process stability.

Description

Lining, reaction chamber and semiconductor processing equipment

Technical field

The present invention relates to the field of semiconductor manufacturing technology, and in particular to a lining, a reaction chamber, and a semiconductor processing apparatus.

Background technique

In the etching process, a large number of process parameters of the plasma reaction chamber must be strictly controlled to maintain high quality etching results. Among them, the optimal design of the internal structure of the chamber plays a decisive role in the process performance of the device itself and the etching result of the process.

At present, a lining is usually added inside the reaction chamber of the etching machine, and the lining is mainly used to improve the effective fluidity of the plasma inside the chamber, and at the same time, can restrain the plasma, and protect the inner wall and the bottom of the chamber from being etched. . In addition, the added lining is more convenient for the maintenance of the machine room.

The existing inner liner is disposed around the inner side of the side wall of the reaction chamber, and the upper end of the inner liner is grounded, and the lower end of the inner liner is provided with a horizontal bending portion bent toward the inner side thereof and a vertical upward portion from the horizontal bending portion a bent vertical bend, wherein a vertical bend surrounds the base for changing the impedance model of the base and its surroundings, enhancing the electric field strength at the edge of the base, thereby increasing the wafer The etching efficiency of the edge can further improve the etching uniformity of the wafer. The horizontal bend is used to prevent plasma from passing through the gap between the liner and the pedestal and entering the bottom of the chamber to protect the bottom of the chamber from being etched.

The above liners inevitably have the following problems in practical applications:

Since only the upper end of the lining is grounded, the inner lining loop is long in the radio frequency environment, and the bent structure of the inner lining exhibits a large inductance characteristic, and a capacitance characteristic is formed between the vertical bent portion and the pedestal. Thus the liner is equivalent to form an equivalent model as shown in FIG. The formula for the resonant frequency of this equivalent model is:

Where f is the resonant frequency; L is the equivalent inductance, which is produced by the bent structure of the inner liner; C is the equivalent capacitance generated by the vertical bent portion and the base. When the frequency of the RF environment is close to the resonant frequency of the system, the system generates resonance, which causes the DC self-bias of the RF environment to be abrupt. As shown in Figure 2, the DC self-bias voltage suddenly decreases, and an abnormal curve appears, which affects the process stability.

Summary of the invention

The present invention aims to at least solve one of the technical problems existing in the prior art, and proposes a lining, a reaction chamber, and a semiconductor processing apparatus, which can avoid resonance of the system, thereby enhancing process stability.

In order to achieve the object of the present invention, an inner liner is provided which is disposed in a reaction chamber, the inner liner comprising:

a lining body disposed around the side wall of the reaction chamber and grounded;

a first split body surrounding a susceptor disposed in the reaction chamber, and a lower end of the first split body is grounded through the base; and, in an inner peripheral wall of the first split body a media ring is disposed around the outer peripheral wall of the base;

a second body disposed between the lower end of the lining body and the outer peripheral wall of the first body.

Optionally, the second split body is integrally connected with the lining main body.

Optionally, the second split body is integrated with the first split body.

Optionally, the lining body is integrally connected with the second split body; the second split body is integrally connected with the first split body.

Optionally, a lower end of the first split ring protrudes vertically downward with respect to a lower end surface of the second split body.

Optionally, an upper end of the first split body is flush with an upper end of the dielectric ring; a lower end of the first split body is flush with a lower end of the dielectric ring.

As another technical solution, the present invention also provides a reaction chamber in which a susceptor is disposed, and the above-mentioned lining provided by the present invention is further disposed in the reaction chamber.

Optionally, the base includes a base body, an isolation layer, and a metal interface disk disposed in sequence from top to bottom, wherein the metal interface disk is grounded;

The lower end of the first split body is electrically connected to the metal interface disk.

Optionally, the metal interface disk includes a first protrusion protruding from a peripheral wall of the isolation layer;

a second boss protruding from an outer peripheral wall of the first split body is disposed at a lower end of the first split body, the second boss and the first boss are overlapped with each other, and both Secure the connection by screws.

Optionally, a conductive layer is disposed between the two surfaces of the second boss that are in contact with the first boss.

Optionally, the conductive layer is disposed on at least one of the two surfaces of the second protrusion contacting the first boss by electroplating.

As another technical solution, the present invention also provides a semiconductor processing apparatus comprising the above reaction chamber provided by the present invention.

The invention has the following beneficial effects:

The invention provides an inner liner comprising a liner main body, a first split body and a second split body, wherein the liner main body is disposed around the side wall of the reaction chamber and is grounded. The first split body surrounds the base, and the lower end of the first split body is grounded through the base, and a medium ring is disposed between the inner peripheral wall of the first split body and the outer peripheral wall of the base. The second split body is disposed between the lower end of the inner liner and the outer peripheral wall of the first split body for preventing plasma from passing through the gap therebetween. Since the lower end of the first split body is grounded through the base, the capacitance generated by the first split body and the base alone cannot resonate. In addition, the capacitance generated between the first body and the body of the lining is much smaller than the capacitance generated by the first body and the pedestal, and the inductance of the lining is small due to the grounding of the lower end of the first body. Therefore, according to the formula of the resonant frequency, the resonant frequency of the system is greatly increased, so that the frequency of the radio frequency environment is difficult to approach the resonant frequency of the system, thereby avoiding resonance of the system, thereby enhancing process stability.

The present invention provides a reaction chamber which can avoid resonance of the system by using the above-mentioned inner liner provided by the present invention, thereby enhancing process stability.

The semiconductor processing apparatus provided by the present invention can avoid resonance of the system by using the above-mentioned reaction chamber provided by the present invention, thereby enhancing process stability.

DRAWINGS

1 is an equivalent model diagram of an equivalent formation of a conventional liner;

Figure 2 is a graph of self-bias obtained using an existing liner;

Figure 3A is a cross-sectional view of a reaction chamber employed in a first embodiment of the present invention;

Figure 3B is a cross-sectional view of the inner liner according to the first embodiment of the present invention;

3C is an equivalent model diagram of the formation of the inner liner according to the first embodiment of the present invention;

Figure 4 is a cross-sectional view of a liner provided by a second embodiment of the present invention;

Figure 5 is a cross-sectional view of a liner provided by a third embodiment of the present invention;

6A is a cross-sectional view of a liner of a reaction chamber according to a fourth embodiment of the present invention;

Fig. 6B is an enlarged view of the area I in Fig. 6A.

Detailed ways

In order to enable those skilled in the art to better understand the technical solutions of the present invention, the lining, the reaction chamber and the semiconductor processing apparatus provided by the present invention are described in detail below with reference to the accompanying drawings.

Referring to FIG. 3A and FIG. 3B together, a first embodiment of the present invention provides an inner liner disposed in the reaction chamber 6. The reaction chamber 6 is further provided with a base 1 for carrying the workpiece to be processed. And the base 1 is grounded. The inner liner includes a liner main body 2, a first split body 32, and a second split body 31. Wherein, the lining main body 2 is disposed around the side wall of the reaction chamber 6 and is grounded. In this embodiment, the upper end of the lining main body 2 is connected to the side wall of the reaction chamber 6, and is electrically connected, and the reaction chamber The side wall of the chamber 6 is grounded to achieve grounding of the lining body 2.

The first split body 32 surrounds the base 1 and the lower end of the first split body 32 is grounded through the base 1 and in the space D1 between the inner peripheral wall of the first split body 32 and the outer peripheral wall of the base 1 A media ring 4 is provided. The second split body 31 is disposed between the lower end of the inner liner main body 2 and the outer peripheral wall of the first split body 32 for preventing plasma from passing through the gap between the inner liner main body 2 and the first split body 32, and diffusing to the reaction The bottom of the chamber 6.

Since the surface of the susceptor 1 and the plasma sheath exhibit a capacitive effect and generate an electric field, the electric field is twisted outward at the edge of the susceptor 1 to cause a reduction in field strength, thereby causing etching efficiency at the edge of the wafer. reduce. To this end, the first split body 32 and the base 1 can be produced by providing the first split body 32 while providing the medium ring 4 between the inner peripheral wall of the first split body 32 and the outer peripheral wall of the base 1. The capacitance is C1, which can change the impedance model of the susceptor 1 and its surrounding environment, and enhance the electric field strength at the edge of the pedestal, thereby improving the etching efficiency of the wafer edge and thereby increasing the etch uniformity of the wafer. The dielectric ring 4 described above can function to increase the capacitance C1, which can be made, for example, of ceramic.

In practical applications, according to the respective roles of the first split body 32 and the second split body 31, the radial thickness of the first split body 32 is much smaller than the axial length thereof, that is, the first split body 32 has a cylindrical shape to ensure It forms a capacitive effect with the susceptor 1. As for the second split body 31, its radial thickness is such that it can block the gap between the lower end of the lining main body 2 and the outer peripheral wall of the first split body 32. Optionally, the second split body 31 is an annular plate body.

Optionally, the lower end of the first split body 32 protrudes vertically downward with respect to the lower end surface of the second split body 31 to facilitate grounding.

In addition, optionally, the upper end of the first split body 32 is flush with the upper end of the dielectric ring 4; the lower end of the first split body 32 is flush with the lower end of the dielectric ring 4 to increase the first split 32 and the base. Block 1 produces a capacitor C1.

In the present embodiment, the second split body 31 is integrally formed with the lining main body 2, in other words, the second split body 31 is a horizontal bent portion formed by bending the lower end of the lining main body 2 inward. Further, the free ends of the second split body 31 are spaced apart from the outer peripheral wall of the first split body 32 by a distance D2, thereby achieving separation of the first split body 32 from the lining main body 2. It should be noted that the separation distance D2 between the free end of the second split body 31 and the outer peripheral wall of the first split body 32 should be reduced as much as possible to prevent plasma from passing through the gap between the two. At the same time, when the separation distance D2 is sufficiently small, the free end of the second split body 31 corresponds to the ground.

Since the lower end of the first split body 32 is grounded through the susceptor 1, the equivalent model formed by the inner liner is as shown in FIG. 3C, and the capacitance C1 generated by the first split body 32 and the susceptor 1 alone cannot resonate. Moreover, the capacitance C2 generated between the first split body 32 and the lining main body 2 is much smaller than the above-mentioned capacitor C1, and at the same time, since the lower end of the first split body 32 is grounded through the susceptor 1, the lining main body 2 is opposite. In the prior art, there is no vertical bending portion, so that the inductance is small, so that according to the formula of the resonance frequency, since the capacitance C2 and the inductance are greatly reduced, the resonance frequency of the system is greatly increased, and the frequency of the radio frequency environment is very high. It is difficult to access the resonant frequency of the system, which in turn avoids resonance in the system and thus enhances process stability.

Referring to FIG. 4, the reaction chamber provided by the second embodiment of the present invention is different from the first embodiment described above in that the structure of the first split body 32 and the second split body 31 are different.

Specifically, the lining main body 2 and the second split body 31 are integrally connected; the second split body 31 is integrally connected with the first split body 32. The second split body 31 is a horizontal bent portion that is bent inward from the lower end of the lining main body 2, and the free end of the horizontal bent portion is integrally connected with the outer peripheral wall of the first split body 32. This also makes the inner liner form an equivalent model as shown in FIG. 3B, so that it is difficult to approach the resonance frequency of the system in the frequency of the radio frequency environment, thereby avoiding resonance of the system, thereby enhancing process stability.

Referring to FIG. 5, a reaction chamber according to a third embodiment of the present invention is different from the first and second embodiments described above in that the first split body 32 and the second split body 31 have different structures.

Specifically, the second split body 31 is integrally connected with the first split body 32, that is, the inner peripheral wall of the second split body 31 is integrally connected with the outer peripheral wall of the first split body 32, which can also form the inner liner as shown in the figure. The equivalent model shown in 3B. Moreover, since the circuit of the lining main body 2 is further shortened, the inductance of the lining main body 2 is further reduced. Further, there is a space D3 between the outer peripheral wall of the second split body 31 and the lining main body 2, and the interval D3 should be reduced as much as possible to prevent plasma from passing through the gap therebetween.

In summary, the lining provided by the above various embodiments of the present invention can avoid resonance of the system by using a split structure, thereby enhancing process stability.

As another technical solution, the embodiment of the present invention further provides a reaction chamber having a structure similar to that of the reaction chamber 6 shown in FIG. 3A, a susceptor 1 is disposed in the reaction chamber 6, and the present invention The inner liners provided by the various embodiments described above.

In the present embodiment, as shown in FIG. 6A, the susceptor 1 includes a susceptor body 11, a separator 12, and a metal interface disk 13 which are disposed in this order from top to bottom, wherein the susceptor body 11 is used to carry a wafer. The isolation layer 12 is made of an insulating material such as ceramic for electrically insulating the base body 11 from the metal interface disk 13. The metal interface disk 13 is grounded. Further, the lower end of the first split body 32 is grounded by being electrically conducted to the metal interface disk 13.

In order to ensure that the lower end of the first split body 32 is electrically connected to the metal interface disk 13, as shown in FIG. 6B, the metal interface disk 13 includes a first boss 131 protruding from the outer peripheral wall of the isolation layer 12; The lower end of the split body 32 is provided with a second boss 321 protruding from the outer peripheral wall of the first split body 32. The second boss 321 and the first boss 131 are overlapped with each other, and the two are fixed by screws 5. connection. By the second boss 321 and the first boss 131, the contact area of the first split body 32 and the metal interface disk 13 can be increased, thereby ensuring good electrical conduction between the lower end of the first split body 32 and the metal interface disk 13.

Further preferably, a conductive layer (not shown) is disposed between the two surfaces of the second boss 321 in contact with the first boss 131 for making the second boss 321 and the first boss 131 Good contact. Specifically, the conductive layer may be disposed on at least one of the two surfaces of the second protrusion 321 contacting the first boss 131 by electroplating, that is, the conductive layer may be plated on the second protrusion 321 The lower surface, and/or the upper surface of the first boss 131.

The reaction chamber provided by the embodiment of the present invention can avoid resonance of the system by using the inner liner provided by the above various embodiments of the present invention, thereby enhancing process stability.

As another technical solution, an embodiment of the present invention further provides a semiconductor processing apparatus including the reaction chamber provided by the above various embodiments of the present invention.

The semiconductor processing apparatus provided by the embodiments of the present invention can avoid resonance of the system by using the reaction chamber provided by the above various embodiments of the present invention, thereby enhancing process stability.

It is to be understood that the above embodiments are merely exemplary embodiments employed to explain the principles of the invention, but the invention is not limited thereto. Various modifications and improvements can be made by those skilled in the art without departing from the spirit and scope of the invention, and such modifications and improvements are also considered to be within the scope of the invention.

Claims

An inner liner disposed in the reaction chamber, wherein the inner liner comprises:

a lining body disposed around the side wall of the reaction chamber and grounded;

a first split body surrounding a susceptor disposed in the reaction chamber, and a lower end of the first split body is grounded through the base; and, in an inner peripheral wall of the first split body a media ring is disposed around the outer peripheral wall of the base;

a second body disposed between the lower end of the lining body and the outer peripheral wall of the first body.
The liner of claim 1 wherein said second body is integral with said liner body.
The liner of claim 1 wherein said second body is integral with said first body.
The lining of claim 1 wherein said lining body is integral with said second body; said second body being integral with said first body.
The inner liner according to any one of claims 2 to 4, wherein a lower end of the first split ring projects vertically downward with respect to a lower end surface of the second split body.
The inner liner according to any one of claims 1 to 4, wherein an upper end of the first split body is flush with an upper end of the medium ring; a lower end of the first split body and the medium The lower ends of the rings are flush.
A reaction chamber in which a susceptor is provided, wherein a lining according to any one of claims 1 to 6 is further provided in the reaction chamber.
The reaction chamber according to claim 7, wherein the base comprises a base body, an isolation layer and a metal interface disk disposed in order from top to bottom, wherein the metal interface disk is grounded;

The lower end of the first split body is electrically connected to the metal interface disk.
The reaction chamber according to claim 8, wherein said metal interface disk comprises a first boss projecting with respect to a peripheral wall of said spacer layer;

a second boss protruding from an outer peripheral wall of the first split body is disposed at a lower end of the first split body, the second boss and the first boss are overlapped with each other, and both Secure the connection by screws.
The reaction chamber according to claim 9, wherein a conductive layer is disposed between the two surfaces of the second boss that are in contact with the first boss.
The reaction chamber according to claim 10, wherein said conductive layer is plated on at least one of two surfaces of said second boss that is in contact with said first boss .
A semiconductor processing apparatus comprising the reaction chamber of any of claims 7-11.